Multi-band coaxial ring-focus antenna with co-located subreflectors

A multi-band ring focus antenna system includes a main reflector that is operable at a plurality spectrally offset frequency bands. A first feed includes a first feed horn and a first sub-reflector, which are positioned spaced apart from each other at respective locations along a boresight axis of the main reflector. The locations are selected so that the first feed horn and the first sub-reflector share a commonly located first phase center. A second feed designed for operation on a second RF frequency band includes a second feed horn and a second sub-reflector, each positioned at a location along the boresight axis of the main reflector so that they share a commonly located second phase center.